Cigarette filter tow



United States Patent 3,476,120 CIGARETTE FILTER TOW John E. Kiefer and George P. Touey, Kingsport, Tenn., assignors to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey No Drawing. Continuation of application Ser. No.

509,463, Oct. 18, 1965, which is a division of application Ser. No. 215,534, Aug. 8, 1962, now Patent 'No. 3,227,791, dated Jan. 4, 1966. This application Dec. 11, 1968, Ser. No. 785,038

Int. Cl. A24d 1/06; A24c 5/48, 5/50 US. Cl. 131-467 1 Claim ABSTRACT OF THE DISCLOSURE This invention relates to a tobacco smoke filter. More particularly, it concerns a filter comprising filaments containing a built-in polyalkylene glycol. This application on our above said tobacco smoke filter is a continuation of application Ser. No. 509,463, now abandoned and which was divisional application of our previous application Ser. No. 215,534, filed Aug. 8, 1962, and now issued as US. Patent 3,277,791. In our companion US. Patent No. 2,904,050 we have disclosed the addition of waxes such as polyalkylene glycol waxes to filament filters as media adhering to the external surfaces of the filaments. In Ser. Nos. 185,824 and 185,825 filed on Apr. 9, 1962, both now abandoned, inventor Touey has disclosed the addition of certain phenol-removing agents to web-type filters. Although such filters have proved highly satisfactory, difiiculties have sometimes been encountered due to possible sloughing oif of additives, uneven and non-uniform dis tribution thereof, softening or weakening of the filter material, channelling of tobacco smoke without impinging thereon, and the like. It is therefore apparent that the production of a filament filter containing a built-in polyalkylene glycol represents a highly desirable result.

It is accordingly one object to this invention to provide a tobacco smoke filter tow comprising continuous filaments containing embodied therein or built therewithin a polyalkylene glycol.

In its broader aspects of invention involves the production of a tobacco smoke filter, the continuous filaments of which contain a built-in polyalkylene glycol, by incorporation of said polyalkylene glycol uniformly throughout the tow from which the filter is formed. The polyalkylene glycol is built into the filaments of the tow and the filters produced therefrom by adding it to the spinning solution prior to extrusion of the tow forming filaments. The filaments preferred for dispersion of the polyalkylene glycols substantially evenly therethrough according to our invention are cellulose esters, particularly cellulose acetate. According to our invention the tobacco smoke filters contain filaments which consist of intimate mixtures 3,476,120 Patented Nov. 4, 1969 "ice of the principal filter-forming material, as exemplified by cellulose acetate, with a polyalkylene glycol. The filament filters of our invention preferably contain from about 130% by weight of a polyalkylene glycol and from 99 to by weight cellulose acetate as described in our Patent 2,904,050, the optimum amount of polyalkylene glycol being 3-25% by weight and of cellulose acetate 97 to by weight.

The polyalkylene glycols which we have found useful in carrying out our invention include polyethylene glycols which contain 8 to 1,000 polyoxyethylene groups in their chain and polypropylene glycols which contain 8 to 100 polyoxypropylene groups in their chain. Other materials which may be used in other embodiments include mixed polyethers containing both polyoxyethylene and polyoxypropylene groups and esters and ethers thereof, for example, the distearate ester of polyethylene glycol, the alkylphenoxy polyethoxy ethanols and the glycerol ethers of the polyalkylene glycols.

Preferred types of cellulose acetate which may be used in accordance with our invention are those containing an average of 2 to 3 acetyl groups per glucose unit. The cellulose acetate may also contain minor amounts of other acetyl groups such as propionyl or butyl.

While the tow which may be prepared according to my invention may be of a wide range of denier per filament, total denier and crimps per inch, the optimum denier per filament is less than about 9, preferably about 1.6 to 4, total denier less than about 80,000 the crimps per inch at least about 7, preferably 7-16.

In forming the tow by extrusion from a spinning solution, the solvents for the filament-forming material and polyalkylene glycol which may be used include ketones such as acetone and methyl ethyl ketone, chlorinated hydrocarbons and esters such as ethyl acetate and the like. The tow throughout the filaments of which the polyalkylene glycol is embedded may be spun, for example, from a solution under pressure forced through the small holes or orifices of a spinneret. The filaments may be continuously pulled from such a spinneret through a spinning cabinet wherein the solvent is evaporated by means of a hot gaseous medium such as air.

The filaments may then be crimped and bundled to gether as tow and the tow further processed and cut into filter rods. Additional firmness may be imparted to the filter as desired by treatment with a plasticizer such as glycerol triacetate, triethyl citrate, dimethoxy ethyl phthalate, or the like before being wrapped.

A further understanding of our invention may be obtained by reference to the following examples which are intended to be illustrative only. Percent refers to percent by weight unless otherwise indicated.

EXAMPLE I A spinning solution was prepared consisting of 25% cellulose acetate (39.8% acetyl) and 75% of acetone. The solution was divided into eight 1 kg. samples. One sample was used as a control. A polyglycol was added to each of the other samples. In each case acetone was added with the polyglycol so that the final solution contained 25% nonvolatiles (cellulose acetate plus polyglycol). Each solution was heated to 50 C. and mixed for 30 min., then spun into 3.8 denier per filament fibers using a cellulose acetate spinning cabinet. Nineteen thousand of the filaments were pulled together to form a tow. The tow was crimped to 16 crimps per inch. It was then compacted into the form of a card and processed into filter rods on a standard cigarette filter rod making machine. The rods which had a circumference of 26.5 mm. were cut into 15 mm. lengths and attached to a domestic brand of cigarettes. The cigarettes were smoked on an automatic smoking machine. The smoke was collected and analyzed for its phenol content according to the method described by Rayburn, Harlan, and Hanmer in Analytical Chemistry, vol. 25, p. 1419 (1953) The results are listed in the following table.

Phenol found In smoke from 100 filtered cigarettes, Composition of Fiber milligram Run: 7

1- 100% Cellulose acetate 10 2- 95% Celluilgsfi) acetate plus 6% polyethylene glycol 4 3. 90% C eliulgge acetate plus 10% polyethylene glycol 4 4- 85% Cellulose acetate plus 15% polyethylene glycol 3 (M.W. 4,000). 5- 75% Cellulose acetate plus 25% polyethylene glycol 2 (M.W. 4,000). 6 90% Cellulose acetate plus polyethylene glycol 3 (M.W. 4,000). 7 90% Cellulose acetate plus 10% polypropylene glycol 5 (M.W. 2,000). 8- 90%Gellulose acetate plus 10% condensate of ethy- 5 lens oxide with polyoxypropylene. 9- Unfiltered cigarette 22 EXA-MPLE II A spinning solution was prepared consisting of 25% cellulose triacetate and 75% solvent. The solvent consisted of 90% methylene chloride and 10% methanol. The spinning solution was divided into 2 portions. Poly(ethylene glycol) (M.W. 600) was added to one portion. Each solution was spun into fibers using a cellulose acetate spinning cabinet. The fibers were converted into cigarette filters and attached to cigarettes as in Example I. The cigarettes were smoked on an automatic smoking machine and the smoke was collected and analyzed for its phenol content. The smoke obtained from 100 cigarettes with the cellulose triacetate filter contained 9 mg. of phenol. The smoke obtained from 100 cigarettes with the filter made from the cellulose triacetate-poly(ethylene glycol) fibers contained only 4 mg. of phenol.

From the foregoing description it will be apparent that by our invention we have provided a polyalkylene glycolcontaining tow product which differs from a yarn product in as many ways as and more than yarn differs from tow. For instance, in the case of yarn the individual filaments from a single spinning cabinet shortly after being formed are wound up as yarn on bobbins or the like and thus have imparted thereto at least some twist. On the other hand, in the case of tow, as in this invention, thousands of filaments from several spinning cabinets are combined as crimped tow, the crimping being performed shortly after spinning. Yarn might be described as harsh or stringy in nature, a desirable feature for garment manufacturing purposes, whereas tow, for example, for use in cigarete filters, is comparatively smooth, porous, or cottony in appearance.

Although the invention has been described in considerable detail with particular reference to certain preferred embodiments thereof, variations and modifications can be effected within the spirit and scope of the invention as described hereinabove, and as defined in the appended claim.

We claim:

1. A tobacco smoke filter tow of crimped cellulose ester fibers, said tow being formed from continuous filaments of cellulose acetate or cellulose triacetate having uniformly dispersed within and on the said filaments about 3 to 25 by weight of a polyethylene or polypropylene glycol having between about 8 to repeating oxyalkylene units, said tow having 7 to 16 crimps per inch and manifesting a total denier of 20,000 to 75,000 and a denier per filament of 1.6 to 4, said tow when formed into plugs and in use, being effective in removing phenols from the smoke stream.

References Cited UNITED STATES PATENTS 3,173,427 3/1965 Tamblyn et al. l31269 X 2,956,329 10/1960 Touey 131267 X 3,032,445 5/1962 Hamon 131-269 X 3,032,829 5/1962 Mahoney et al.

FOREIGN PATENTS 208,278 3/ 1960 Austria.

MELVIN D. REIN, Primary Examiner U.S. Cl. X.R. l31269; 156180 Pg ggo UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION 3,476,120 November I, 1969 Patent No. Dated Inventor) John E. Kiefer and George P. TQuev It is certified that error appears in the above-identificd patent and that said Letters Patent are hereby correczed as shown below:

I Column 1, line 35, Patent No. "3,277,791" should be 3,27,791-- line 5 "of" should be -our--. Column 2, 'line 29, the' should be and--.

SIGNED AND SEALED MAY 1 21970 (SEAL) Atteat:

WILLIAM E. SCEHUYLER, JR. Edward M. Fle I Commissioner of PatewLs Attesting Officer 

